Energy-efficient optical system for excimer laser ablation apparatus

To improve the capabilities of excimer laser ablation processing apparatus, we have been developing an innovative Multiple Irradiation Optical System (multiple irradiator). In this system, we placed a reflector opposite the mask, and used a mask with a highly reflective coating. The laser beams therefore irradiate the mask repeatedly, and we can use the laser energy more efficiently than conventional optical systems. The experimental results show that our system is 12 times more energy efficient than the conventional optical systems. Also, we have made a prototype excimer laser material processing apparatus with the multiple irradiator, which is suitable for drilling viaholes of less than 100 micrometers diameters such as viaholes of print circuit boards. The processing speed is less than 1 minute when the material is 100 mm X 100 mm wide and 25 micrometers thicknesses polyimide film, and the laser energy is 40 mJ/shot with 600 Hz frequency.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.